From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id DEBE4C61DBD for ; Wed, 26 Aug 2026 13:22:11 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D37D06B008A; Wed, 26 Aug 2026 09:22:10 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CE5D46B009B; Wed, 26 Aug 2026 09:22:10 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BFBFD6B009D; Wed, 26 Aug 2026 09:22:10 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 9447B6B008A for ; Wed, 26 Aug 2026 09:22:10 -0400 (EDT) Received: from smtpin29.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 15188140379 for ; Wed, 26 Aug 2026 13:22:10 +0000 (UTC) X-FDA: 85143484020.29.51745FF Received: from mta1.migadu.com (out-152.mta1.migadu.com [95.215.58.152]) by imf06.hostedemail.com (Postfix) with ESMTP id BDDD7180006 for ; Wed, 26 Aug 2026 13:22:07 +0000 (UTC) Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=CVvqQQM1; spf=pass (imf06.hostedemail.com: domain of usama.arif@linux.dev designates 95.215.58.152 as permitted sender) smtp.mailfrom=usama.arif@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1787750528; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=rZfJ1DEJgA9xHP174GM+zD+DDhRxQ3ktuVvCLdq3Www=; b=oMhkf2dfukg1JTs42ezPu8UurHhF1U1tc51zHiEmkxNnveQbMrmI4i5cxPFaUwKmSDLAqf GUIEch5B+HXso3HveneeZdNqCsPta3h2rx3EFKsgUvQsw4bx+hY+PqH6Z71x8sLsO+yZPJ /7LMo4PsRnRnr61zCfFR83iKSxXB3jg= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1787750528; b=GKc23nykcxyrQ4VbXg+mKsXSzOjfIKpMBCoUhkp/lF3Hp51uK6sYgEpegRPJjSuwlYcjJr aLjdx1062TKU5aOd+iicDS795AGRoUGxyqog6ROOqKbZPcYi+nR4oqByfKfImkjV1NP+UA B/reAr1UzBm9aGh6ML969J16dzb02eE= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=CVvqQQM1; spf=pass (imf06.hostedemail.com: domain of usama.arif@linux.dev designates 95.215.58.152 as permitted sender) smtp.mailfrom=usama.arif@linux.dev; dmarc=pass (policy=none) header.from=linux.dev X-Envelope-To: linux-mm@kvack.org DKIM-Signature: a=rsa-sha256; bh=MbqC4/3XY2Q8MsrJW7NGpu6sTdEBe8KkMt4dCMJF8g4=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1787750526; v=1; x=1788355326; b=CVvqQQM184Jm75RDtC4a1OO4/F7nTy91v4NJKILsAAfjDf7M+JdN0EoD4RkwoK4jJsR6HVbO gy/aYQ9o+uksKAvOLOQ8kBPluU7m7BtlvRg/I2cuMJFO6W5nvjlC5c6fE8wMd05ep0I+a8cZzW0 mbjh4aiJtP0Ixz0Bcde12QLU= X-Envelope-To: linux-mm@kvack.org Received: from localhost (2a03:2880:10ff:19::) by mta10.migadu.com with ESMTPS id ee22d32ad11dbb84; Wed, 26 Aug 2026 13:22:06 +0000 X-Mizu-Trace-ID: ee22d32ad11dbb84 X-Migadu-Flow: FLOW_OUT From: Usama Arif To: Alexandre Ghiti Cc: Usama Arif , Johannes Weiner , Yosry Ahmed , Nhat Pham , Chengming Zhou , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Hugh Dickins , Baolin Wang , Chris Li , Kairui Song , Kemeng Shi , Baoquan He , Barry Song , Youngjun Park , Qi Zheng , Shakeel Butt , Axel Rasmussen , Yuanchu Xie , Wei Xu , Joonsoo Kim , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 1/3] mm/swap: move LRU insertion out of the swap cache allocator Date: Wed, 26 Aug 2026 06:21:58 -0700 Message-ID: <20260826132159.433469-1-usama.arif@linux.dev> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260825172604.3243589-2-alex@ghiti.fr> References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: BDDD7180006 X-Stat-Signature: 3rxtudxtf3xxz61h3hr3te8b7aa9ract X-HE-Tag: 1787750527-139599 X-HE-Meta: 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 tqL9J7ir noYC305wedN7FtDxXnDIwqFQWkXQxE/0mxpNl/T90Qpkr7fJm70FyP+1ZnONmRHwUVDTvC4S6TQoSVpPmpqkyJyG5JsLkdjeHk7Cw6ESHz6LleLEk7bbxVTe0ZbD2QtPgz+XNeEV+3kPh+nL79k7PQ7ANt8BFj9KmzEcLjuCkcDUeJqhFUJ5X31EVH20cJHCYT84/eNxfcPMDfOhooWfg9GTbuwzkvv9rI2Raxr6z2BXrveR5csQ7ICsO3+s3ZHhwe3mm8YIfocWUuZus9pJ1msFjDhVsGMDd6tik5oQxClARr8U= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, 25 Aug 2026 19:24:51 +0200 Alexandre Ghiti wrote: > This is a preparatory patch. > > __swap_cache_alloc_folio() adds the new folio to the LRU itself, which > leaves its callers no way to act on the folio before it becomes visible > to reclaim. Two users need exactly that: > > - the next patch moves the refault evaluation out of the swap cache > folio allocation, and it has to happen before folio_add_lru(): that > consumes PG_active to file the folio on the inactive or the active > list, and under MGLRU it also reads PG_workingset to pick the > generation. Setting either flag afterwards does not move the folio; > > - the upcoming zswap writeback dropbehind implementation needs the > buffer folio to stay off the LRU entirely, as the per-CPU LRU batch > would hold a reference on it and keep remove_mapping() from freeing > it once writeback completes. > I think the kernel convention is to not say "next patch" and "upcoming.." Especially as this patch is in 2 series, so you don't know where it will land. > Defer the LRU insertion to the callers of __swap_cache_alloc_folio(): > each of them adds the folio right after the allocation, so there is no > functional change intended. > > Suggested-by: Kairui Song > Signed-off-by: Alexandre Ghiti The code change itself looks good to me, so once the commit message is fixed: Acked-by: Usama Arif